I live in Victoria, BC, Canada. I will be building a freestanding building in my back yard to be used primarily as a jam space and rough demo recording space (and secondarily as a small home office). I do not need perfect sound treatment inside since it is mostly for rock band practices, but I wouldn't say no to a nice sounding room. The most important acoustic feature is soundproofing from the neighbours, who are 20 feet away on one side and the 30 feet behind. A little bit of bleed is okay, because we are in a central, urban area, but I would like to be able to play with a full band without having the cops called.
The building will be 15'x18' (but we could go up to 16'x20' if that improves the acoustics).
1. Walls: I plan to frame two 2x4 walls, with plywood and wood siding on the exterior and 1/2" gypsum on the interior. The walls will each have R14 Roxul insulation batts and there will be a 1" air space between the walls. Please let me know if there are ways I can improve this wall assembly for soundproofing.
2. Ceiling: The ceiling will be sloped from 8 ft on the sides to 11 ft at the peak. I suppose I have to use the same principle as the walls for the ceiling, with a double rafter system. If not, finishing could be difficult and I may lose the soundproofness. Should I hang a second ridge beam from the main exterior one using hooks? How, if at all, would you ventilate a double rafter roof?
3. Windows: There will be one or two windows. Rather than pay for special soundproof glass, I was hoping to make some soundproofing window inserts that I could put in when it gets late and/or loud. I figured I would just frame around an insulation batt with 2x4s. Any ideas about how effective this would be?
4. Floor: One of my major planning decisions is the floor. Much easier than pouring concrete would be building a 2x8 framed floor on piers. I would insulate the joist cavities, then lay 3/4" plywood and 5/8" oak floors. How would this compare sonically to starting on a poured slab? Are there reasonable ways around pouring concrete that will produce good results? I have a lot of bricks around, for instance.
5. Heat: A 1500W electric baseboard heater should be enough to heat the room. It may even be overkill given the airtightness and insulation levels. We don't need cooling in our mild climate.
6. Ventilation: The final decision I have is how to ventilate the space without sacrificing the soundproofness. Chances are, the space will only be used for maximum 3 hours at a time, so I am not opposed to the idea of a ventilation system I can shut down while it's loud and turn on when it's not. However, if there is a good solution for ventilation, I would love to hear it!
I have estimated my budget to be around $5,000 using standard construction materials (and doing all the work myself). If there are better insulation materials, for example, or a worthy mechanical ventilation system, I can spend up to $10,000.
Thanks for your input.
Garden shed jam space, new construction
Originally posted at johnlsayers.com, topic 18329.
Hi there "bcbrooke", and welcome! :)
It would be good if you could put numbers to that, in terms of how many decibels of isolation you need. If you don't have a sound level meter already, then pick one up on e-bay or Amazon.com. They are very inexpensive: a decent one will cost you around US$ 75 to 100. (Just stay away from the cheap chines junk, at around US$ 25: garbage). So measure your levels and figure out how much isolation you need.I do not need perfect sound treatment inside since it is mostly for rock band practices, but I wouldn't say no to a nice sounding room. The most important acoustic feature is soundproofing from the neighbours, who are 20 feet away on one side and the 30 feet behind. A little bit of bleed is okay, because we are in a central, urban area, but I would like to be able to play with a full band without having the cops called
1/2" is too thin for acoustics: not rigid enough, the mass is too low, and the resonant characteristics are not exactly overwhelming either! Use only 5/8". Same for the plywood: only 5/8" or 3/4"1. Walls: I plan to frame two 2x4 walls, with plywood and wood siding on the exterior and 1/2" gypsum on the interior.
I think you mean " 1" gap between frames", not " 1" air gap". That's two very different things. With 2x4 studs, if you have a 1 inch gap between your inner frame and your outer frame, then you have an 8 inch air gap! The air gap is the distance between the surfaces of the outer leaf and the inner leaf, across the cavity, regardless of whether or not it is filled with insulation.The walls will each have R14 Roxul insulation batts and there will be a 1" air space between the walls. Please let me know if there are ways I can improve this wall assembly for soundproofing.
Since you are building form the ground up, you have several options. Normally, the attic space under the roof deck needs ventilation, but there are some methods for doing the roof where that is not necessary. You might want to look into those, and see if your local building code allows it. If so, then you can build your roof itself as the outer leaf. If not, then just build the roof normally, and you'll have no choice but to do a three-leaf system up there: your roof deck will be the outer leaf, which will be ventilated, then you'll have a "middle leaf ceiling" that extends across the entire building and seals it, with lots of mass, the the individual inner leaf ceilings on each room.2. Ceiling: The ceiling will be sloped from 8 ft on the sides to 11 ft at the peak. I suppose I have to use the same principle as the walls for the ceiling, with a double rafter system. If not, finishing could be difficult and I may lose the soundproofness. Should I hang a second ridge beam from the main exterior one using hooks? How, if at all, would you ventilate a double rafter roof?
Not a good idea, and not very effective. Also, there's no such thing as "soundproof glass". In fact, there's no such thing as "soundproof anything"! :) Any sufficiently loud sound will penetrate any conceivable barrier. All you can do is attenuate sound to the level you want. So you don't need "special soundproof glass". You just need glass that is thick enough to do the job, and the "thick enough" part depends on how much isolation you need, in terms of decibels. That's the basis for studio design: you need to put a number on your goal, then everything else flows form that. Once you have that goal, as a real-world number, you can check wall, window and door designs that will get you there. If you don't have a number, then it's all just guesswork, and you have no idea if you are wasting money on overbuilding, or wasting time and effort by "underbuilding". The idea is to build it just enough so tit meets your goals. If you don't put enough mass and air into it, then it won't isolate and you'll be very disappointed at the end, with the huge wasted effort. and if you put too much mass and air into it, you'll get fantastic isolation, more than you needed... and waste a lot of money in doing so....3. Windows: There will be one or two windows. Rather than pay for special soundproof glass, I was hoping to make some soundproofing window inserts that I could put in when it gets late and/or loud. I figured I would just frame around an insulation batt with 2x4s. Any ideas about how effective this would be?
It would compare very badly. Floors are critical for isolation, and the very best you can get is a simple, inexpensive concrete slab. Fast, low cost, and highly effective.4. Floor: One of my major planning decisions is the floor. Much easier than pouring concrete would be building a 2x8 framed floor on piers. I would insulate the joist cavities, then lay 3/4" plywood and 5/8" oak floors. How would this compare sonically to starting on a poured slab?
You still need HVAC, because you still need humidification, and you'd be surprised how warm it will get in there, and how fast it will do so, if you don't have a properly designed HVAC system. The isolation system basically means that you wrap the room with two absolutely air-tight, totally hermetic envelopes, as well as multiple layers of extremely thick thermal isolation. Then you'll have several musicians working hard, sweating and heating up the place, plus equipment, plus lights, .... That's a lot of heat that ain't goin' no place! It is staying right there, inside the room, building up and building up.... and the humidity is doing the same: people breath, and they sweat. And the CO2 content ot he air is going up, while the O2 level goes down.... It doesn't take long under those circumstances before things start to get unpleasant... a studio is not like a house: it is double-sealed, hermetic, and thickly insulated. So, you HVAC to control the temperature and humidity levels, and you need vents to bring in the right amount of fresh air, and to exhaust the same amount of stale air, and you therefore needs ducts, fans, and silencer boxes. HVAC is the single most overlooked part of home-studio design, since most people think they don't need it: they do. They think you can just open the door every now and then: you can't. It doesn't work. And they also forget the secondary issue: instruments, microphones and voices are sensitive to changes in temperature and humidity, so the sound of the singers, instruments and mics changes over time, as the conditions change... HVAC is not an optional luxury for a studio: it is a basic necessity.5. Heat: A 1500W electric baseboard heater should be enough to heat the room. It may even be overkill given the airtightness and insulation levels. We don't need cooling in our mild climate.
Silencer boxes. Those are basically just very large plywood boxes, lined with duct liner, and with several baffles inside, that force the air to take a long, zig-zag path through the box. For high levels of isolation, you need one box on each leaf penetration. Search the forum for "silencer box" and "baffle box", and you'll find numerous examples of how to make them. Rod's book also teaches you the basics of how to do all the calculations that you need to design the system correctly, in terms of flow rate, flow velocity, cooling, dehumidification, etc.6. Ventilation: The final decision I have is how to ventilate the space without sacrificing the soundproofness. Chances are, the space will only be used for maximum 3 hours at a time, so I am not opposed to the idea of a ventilation system I can shut down while it's loud and turn on when it's not. However, if there is a good solution for ventilation, I would love to hear it!
That's probably still on the low side. For a 16 x 20 building, that's 320 square feet. At $10,000, that's barely $30 per square foot. I don't know what construction rates are like in your area, but that sounds very much on the low side, even if you do all the work yourself. Call around to a few local contractors, and find out what their basic flat rate per square foot is for building a house in your area. That will give a rough idea of how much this is going to cost you, realistically. - Stuart -I have estimated my budget to be around $5,000 using standard construction materials (and doing all the work myself). If there are better insulation materials, for example, or a worthy mechanical ventilation system, I can spend up to $10,000.